Mill screw-down



, May 12, 1925.

, H. A. LEWIS MILL scnwmown 2 Sheefs-Sheet 1 Filed Nov. 19. 1923 NNI H; A.A LEWIS MILL SCREWfDOWN May 12, 192.5.

Fil-ed Nov. 19. 1923 2 Sheets-Sheet 2 MTR ` or more speeds,

'Patented May 12, 1925.

' UNITED STA Mam@ Tas PATENT caricao HARRY A. LEWIS, OF NORRISTON, PENNSYLVANIA, ASSIGNOR OF ONE-HALF TO i ALAN D. WOOD, 0F PHILADELPHIA, PENNSYLVANIA.

MILL SCREW-DOWN.

Application filed November 19, 1923.

To all 'whom z'zf-mog/ concern.:

Be it known that l, HARRY A. Lewis, a citizen of the United States, and resident ot' Norristown, in the county olL lllontgomery .and State ot Pennsylvania, have invented a new and useful Improvement in Mill Screw- Downs; and 1 do hereby declare the following to be a full, clear, and exact description thereof. I

My invention relates to what is known in the rolling-mill art as a screw-down, that is, mechanism .t'or raising and lowering the top roll in a mill for rolling plates, sheets, bars,

etc.

The main object et niy invention is to provide a screw-down of this character with two lowering the roll may be greatly expedited, as compared with the present method, where the hydraulic rack and pinion is employed. n carrying out my invention, l revolve the nuts as well as the screwbars, said nuts being at the present time screwed or keyed into place in the housings, thereby limiting the. lowering of the roll to the speed of the screw-bar itself. Accordingly at present the speed is governed bythe ability of the screw alone to make the necessary adjustments lon the small. drafts, and in many eases after a piece of metal has beencompleted it is necessary to wait fore the next piece can'enter the rolls, due to the slow speed Ot the screw.

ln the accompanying drawings, Fig. 1V is a plan view ot an ordinary plate niill showing my invention applied thereto; Fig. l 2 is a vertical elevation ot saine, partly in section, and Fig. 3 is an' enlarged detail.

l have illustrated my invention in connec tion with an ordinary plate-mill, comprising the rolls 2 and 3, connected up in the ordinary iiianiier of driving such rolls, but 'as `said mechanism comprises no partot my in-4 vention, it is not necessary to refer to the same in detail.

The rolls 2 and 3 are mounted in suitable housings a, and mounted on the housings are the castings 5, which form the housing support' for the worm-wheels 6 and 7. The upper worm-wheels 6 are justing screws 8, and in order to drive each worm-wheel G, a worm 9 is provided, mounted on the Vshaft 1G, which is driven bythe motor 11.

A worm-wheel 7 is keyed to the upperA end so that the operation ot a considerable time be-l keyed to the l adserial No. 675,743.

ot each nut 12, said nut having a threaded seat 13 to receive the screw 8. The nut 12 is contained within the sleeve 14 of suitable vantitriction metal forming a bearing for said nut, and at the lower end ot said sleeve 14 is the thrust-collar 15 which is adapted to engage the shoulder 16 inthe housing. The lower end of thevnut 12 is provided with the head 17, with the upwardly extending flange '1S `wliich projects up j into the recess 19 toi-ined in the housing. and said iange forms a lubricant channel 20, to which oil or grease may n be supplied in any suitable manner. Suitable washers 21 are interposed between Athe head 1T and the thrust-collar 15.

The worin on the shaft 23 engages the woriirwheel 7, and said shaft 23 is driven by the motor 211.

rlhe speed is obtained in opening up the vmill bv starting the motor 11 okt the screws 8, in the upward direction and starting themotor Qt, controlling'- the nuts 12 in the opposite direction. lt' the speed of these motors and the rotating ot the gearing are the same, the time required in opening up the mill willibe cut in halt over the methods now commonly employed. These speeds can be increased still more by speeding up the nuts, and by decreasing the speed of the screws, tine settings are niore readily obtained.

The revolving of the nuts is only to take ,place while the mill is not rolling, and the only resistance will be that obtained by the ordinary countci'balance weights.' lt will also be understood that a. suitable electrical brake ina-y be employed 'for the motor to hold the nuts in position.

What l claim is:

1. 'lin a millscrew down, the combination with the rolls and housing, ot a screw jeun naled in tlie'housing for moving the rolls, means for driving thel screw comprising a air ot driving elements disposed on opposite sides thereof, for eiiecting longitudinal mitting. the independent driving of one eleother.

2. lin a mill screw down, the combination.

with the rolls and housing, of an adjusting screw for the rolls, power means for driving ,ment'simultaneously with thedriving of the l the screw comprising a pair of reversing motors, 5 and ,screw for effecting independent driving and connections between said motors ing worm, the respective prlsing a -worm of the screw longitudinally an equal proportion by each motor when said motors are driven in unison., v

3. In a mill screw down, the combination with the rolls and housing, of anut journaled in the housing, a screw having threaded engagement with said nut, and means for -rotatin said nut and screw comprising a pair o like gear 4elements each adapted to move' the screw longitudinally an equal proportion when driven alike and in unison and operative independently.

4:. In a mill screw down, the combination with the rolls and housing, of` a nut journaled in the housing, a screw threaded. in said. nut, means for rotating the screw comgear slidably keyed thereto and including a drivingworm, and a driving element for the nut com rising. a worm Wheel keyed tothe nut and `including a drivworms being disposed at opposite sides of the screw.

gagement t erewith, and a thrust-collar on said sleeve engaging the housing.

6. In a mill screw-down, the combination with the rolls and housing, of a screw, means fonturning said screw, a nut engaged by said screw, means for rotating said nut in the opposite direction from said screw, a sleeve surrounding said nut, a thrust-collar recess formed therein, a head at the lower end of said sleeveihaving af lubricant receptacle, said head entering said recess and engaging said thrust-collar.

on said sleeve engaging the housing, said housing having a In testimony whereof I, the said -HRRY' A. LEWIS, .have hereunto set my hand.

HARRY A. LEWIS. 

